A couple of thoughts,
Perch are early spawners and in south/ central OH especially in the shallow lakes you fish, that can be a few weeks after ice out with how fast those waters warm.  We also find them up in the pads as soon as the ice goes out up here. 
On a trip to one of the lakes you mentioned, we were catching them a week before ice up from the boat, on the deep edges of the pads.  Keep in mind that deep water is relative so 6 ft to 3 foot is a HUGE depth change.  So if you work a 50 year area near a weed or pad bed, you can cover that change thoroughly and quickly and if there are perch there, they will probably not leave the confines of that area in a few hours. 
I disagree slightly about minnows in the winter for perch.  Once located and found to be active they will tend to take minnows and you will catch the most aggressive fish on them.  But in most of the lakes you are talking about and in winter in general, perch, crappies and bluegills switch to a mainly invertebrate diet.  Scuds, bloodworms, snails, larvae, are easy pickins and better for their slow metabolisms.  Perhaps others will disagree, but whenever I clean ice perch, they are full of of inverts and I don't ever recall cleaning one full of minnows. 
Putting it together, and kicking up some mud:
My high speed locating method would be to drill my holes as mentioned previously to cover a reasonable area where I can hole hop in a minute or two.  Using your vex (I use regular sonar and assume it works the same) drop the ducer in each hole and figue out where you are on the break, remembering 4.5 to 5.5ft. etc. is significant.  Then work each hole for 5 mins.  I would have 3 rods rigged, a tungsten jig that is tiny yet sinks like a rock, an appropriate bladebait and a jigging spoon.  Check each hole with the jig first, get it to the bottom and pound it in the mud.  Any active perch will come over to check out the distubance as you just kicked up the invert. buffet.   Tip with bait or plastic, your preference as long as it is pink or orange.  If no luck on that, I like the smallest cicada or vibee, rip it good for  few mins to see if they come in.  Then when there are fish around, try the jigging spoon, they may come in on the blade but not be willing to hit it.  Always keep the vex on and watch for weak returns as they tend to sit off the bait a few inches to a few feet and come charging in and grab it.  The higher up off the bottom you can get them, the more likely they are to bite.  We have had perch come up 20 feet in clear water following the bait all the way after kicking the bottom up, the inverts and anything that hatches out of the mud tends to rise. 
Lastly, break your lake down into manageable areas and work a different one until you find fish, then try to duplicate the same situation.  The trip I mentioned came down to very, very specific conditions but ended up being successful by paying fine attention to the details, and fishing areas quickly, staying when we found fish and leaving after 10 mins or less when we didn't.  It is much easier on the ice, travel as lightly as possible, drill, a few rods and the vex, a pocket size box with a few backup lures.  With only a few hours, you don't have time to change lures often.  If you aren't marking, you aren't in the right hole, if you can't catch them on one of those 3 setups, they aren't biting or they aren't perch. 
Sorry for long post, guess my 2 cents turned into an inflated pork project!

Hey Slab,
Just went out and checked the pole, neighbor says I'll dull my blades drilling through the driveway   If I put the door extension pole in the middle adjustment hole and then shorten the 2nd and 3rd bow poles to their shortest position, it sits right up front, about 1/2" off the drive (ice).  So its only when I extend all the supports tight that I have the problem.  Maybe the tent shrank? Or those positions only work if the tent gets strectched out?  I can call it good as it is and I am busy building a ski sled and fixing some chipmunk holes in the canvas.  At least they aren't as destructive as mice. 
Just curious if you recall yours working the same way. 
Thanks,
Steelneyes

Hello all,
Does anyone know what would cause my frabill flip over front bar to be about 6" above the ice?  It was not this way in the past and can't figure out what could have bent or moved.  Just retightened all of the bolts as general maintenance.  But the skirt barely touches the ice.  Can take a few pics in the driveway set up if anyone has any ideas or previous experience with a flip over with this problem.

Thanks,
Steelneyes